I don't recall the name, but on Gravois, east of Bevo Mill, North side of the street, there's a bosnian bakery with a small, very casual restaurant attached to it. Mostly sandwiches made with various grilled meats, boureks (meat and veggie), fries, a salad or two. Very tasty, abundant, and cheap. Maybe your friend could get by with salad and a bourek? In general bosnian food is pretty heavy in the meat dept., so even at the places with a more extensive menu your friend probably won't have any more options than what I've mentioned, and the boureks are probably going to be better from a bakery.